Tim Radford / Climate
News Network
DEC 15, 2019
The way to steer the planet
safely away from overwhelming climate crisis may sound familiar, though it’s
staggeringly ambitious: just use incredibly powerful and ultra-fast computers.
Studies in two separate
journals have called for new thinking about global change. One warns that only a
genuine accommodation with nature can save humankind from catastrophic
change. The other argues that present
understanding of the trajectories of global heating is so uncertain that
what is needed is a global co-operation to deliver what scientists call
exascale supercomputer climate modelling: exascale means calculations at rates
of a billion billion operations a second.
There’s a snag: nobody has yet
built a working exascale computer, though several groups hope to succeed within
a few years. But when it’s done it could transform the prospects of life on
Earth.
“We cannot save the planet –
and ourselves – until we understand how tightly woven people and the natural
benefits that allow us to survive are,” said Jianguo Liu of Michigan
State University, one of the authors of a paper in the journal Science.
“We have learned new ways to
understand these connections, even as they spread across the globe. This
strategy has given us the power to understand the full scope of the problem,
which allows us to find true solutions.”
And Tim Palmer of
Oxford University, an author of a perspective paper in the Proceedings of the National
Academy of Sciences, has called for a new and international investment in
sophisticated climate modelling, exploiting a new generation of computers, in
much the same way that physicists at CERN in
Geneva co-operated to explore the sequence of events in the first
microsecond of creation.
“By comparison with new
particle colliders or space telescopes, the amount needed, maybe around $100
million a year, is very modest indeed. In addition, the benefit/cost ratio to
society of having a much clearer picture of the dangers we are facing in the
coming decades by our ongoing actions, seems extraordinarily large,” he said.
“To be honest, all is needed
is the will to work together across nations, on such a project. Then it will
happen.”
The point made by authors of
the Science study is that humankind depends acutely on the natural world for at
least 18 direct benefits: these include pollination and the dispersal of seeds,
the regulation of clean air, and of climate, and of fresh water, the protection
of topsoils, the control of potential pests and diseases, the supplies of
energy, food and animal fodder, the supplies of materials and fabrics and
yields of new medicines and biochemical compounds.
Massive change
“Human actions are causing the
fabric of life to unravel, posing serious risks for the quality of life of
people”, the authors warn.
“Human actions have directly
altered at least 70% of land surface; 66% of ocean surface is experiencing
cumulative impacts; around 85% of wetland area has been lost since the 1700s
and 77% of rivers longer than 1000 km no longer flow freely from source to
sea.”
There was a need for
“transformative action” on a global scale to address root economic, social and
technological causes and to avert catastrophic decline of the living world.
“Although the challenge is formidable, every delay will make the task harder”,
they warn.
But in a world of rapid change
– with species at increasing risk of extinction and global heating about to trigger
catastrophic climate change – there is still the challenge of working out what
the implications of any change might be.
The argument is that human
society must change, and so too must the scientific community. Climate
modelling might deliver broad answers, but researchers would still need to be
sure what might work best in any particular circumstances, and that would
require new and vastly more complex levels of mathematical calculation and data
interpretation.
Space-race urgency
Professor Palmer and his
colleague Bjorn
Stevens of the Max Planck Institute for Meteorology in Hamburg call
for better understanding of the need for change.
“What is needed is the urgency
of the space race aimed, not at the Moon or Mars, but rather toward harnessing
the promise of exascale supercomputing to reliably simulate Earth’s regional
climate (and associated extremes) globally”, they argue.
“This will only be possible if
the broader climate science community begins to articulate its dissatisfaction
with business as usual – not just among themselves, but externally to those who
seek to use the models for business, policy, or humanitarian reasons.
“Failing to do so becomes an
ethical issue in that it saddles us with the status quo: a strategy that
hopes, against all evidence, to surmount the abyss between scientific
capability and societal needs.”
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